{{ call_a_or_b_on_tail!((a: year, b: month, c: day), call a: 2021, "July", (0+2)) }}
{{ call_a_or_b_on_tail!((a: year, b: month, c: day), call b: 2021, "July", (0+2)) }}
{{ call_a_or_b_on_tail!((a: year, b: day, c: month), call b: 2021, "July", (0+2)) }}
